The present invention is novel derivatives of fenamic acids. Such fenamic acids are related to the fenamic acids in copending application U.S. Ser. No. 248,204 (or published WO 89/03818) so the "Background of the Invention" from this application is pending incorporated by reference.
Additionally, Japanese Application Nos. J63185-924A and J63189-923A (disclosed in Derwent Abstract Nos. 88-25448/36 and 88-25447/36, respectively) and Netherlands Application No. 7008620 (disclosed in Derwent Abstract 009745-B) include hydroxyamino. The present fenamic acid derivatives differ in that a hydroxamate substituent in the present invention is removed from the benzanilino ring system by only one --CHR.sub.2 --group, and the substituent on the phenyl not containing the hydroxamate substituent has only one group which is CO.sub.2 R.sub.1. Other references of interest include U.S. Pat. No. 3,821,268 having a hydroxyamino removed from a benzanilino moiety by an acyl group and U.S. Pat. No. 3,574,737 having a hydroxyamino removed from a benzanilino moiety by an acyloxy group. U.S. Pat. No. 3,413,313 teaches an N-aryl-anthranilic acid having a carboxy on an N-phenyl group with a ketoxime of the formula --C(NOH)lower alkyl. The present invention differs in that N-phenyl group is substituted with a substituted hydroxylamine rather than a ketoxime, and is thus at a different oxidation state.
Thus, the present invention are to selected novel derivatives of fenamates and pharmaceutically acceptable acid addition or base salts thereof, pharmaceutical compositions for treating inflammation, arthritis, pain, pyrrhia, and the methods for such treatment.